Automotive Air Conditioning Information Forum

I'm new to this forum so this may have already been answered by someone, but if someone could help that would be great.
I'm doing retromod on a BMW E9 which did not come out with air conditioning, i've managed to sort most of it out but have come into a problem.
The motor we are putting into the car is also out of a BMW a 2006 130i, the compressor on the motor fits into the space of the E9 engine bay (very tight) but it's a variable displacement compressor, i've had no luck finding a 6 groove old clutch style compressor.
So my question is is there any way i can run the variable displacement compressor with some sort of control unit or have duty cycle controller to manually adjust the cool air

Cheers Dave

Some of the answer depends on the refrigerant metering device in the car the engine is going in to, and some more information on the donor car / engine.

First, all US reference books work from Year / Make / Model / Engine / Sub Model. A BMW "E" number may mean something to an enthusiast, but as far as I can tell the E9 Was made from 1968 to 1975, came with both 4 and 6 cylinder engines.

So I can take a stab in the dark and call the "E9" a 1971 3.0CS. I see a TXV for that car, so a control valve compressor would be a bad choice according to most sources.

The 2006 130i, I have no parts data for that model. Was it not imported to the US? Perhaps as a different model?

According to what I see online the 130i came with three different engines. I am going to guess that you are using the 3.0l I6 for the swap.

The good news is that many 3.0L I6 BMW engines came with Denso compressors OEM. There may be a standard fixed displacement compressor that fits your engine in the Denso line. Can you post a picture or model information on the compressor from the donor car?

I really don't like to guess at this sort of thing. So help us here and fill in some blanks

Scott, you can power and control the variable compressor control valve yourself. It's just an analog coil that produces a force on the control valve.

It's a 12V coil, draws about 1 Amp. If you want to control, it uses a PWM signal at 400Hz. Suction pressure is inversely proportional to the duty cycle of the signal, but discharge pressure also has an influence. Doesn't need to be 12V, battery Voltage is OK,

If you don't want to control it other than On/Off, then straight 12V gets you full compressor displacement, no Voltage is off.